Why is that critical? If a unidirectional bezel is knocked and unintentionally moved on the dive, it could only Display screen an extended underwater time. Which means the wearer will overestimate rather then undervalue immersion time, and in situations that have to have decompression stops, This may be a make-it-or-crack-it https://www.watchesworld.com/frozen-in-time-luxury-watches-for-winter/